Stock-Based Compensation - Additional Information (Detail) - USD ($)					1 Months Ended	12 Months Ended
	Jul. 31, 2016	Jan. 31, 2016	Jul. 31, 2015	Jan. 31, 2015	May 30, 2009	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Aug. 01, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Deferred Compensation Share-based Arrangements, Liability, Current and Noncurrent						$ 0	$ 0	$ 500,000
Grants in period, weighted average grant date fair value						$ 6.04	$ 8.09	$ 3.09
Shares
Options outstanding Beginning Balance						403,000	150,000
Options granted						472,000	280,000
Options exercised						(18,000)	0
Options forfeited						(47,000)	(27,000)
Options outstanding Ending Balance						810,000	403,000	150,000
Weighted Average Exercise Price
Options outstanding Beginning Balance						$ 15.07	$ 12.97
Options granted						16.20	16.35
Options exercised						13.33	0.00
Options forfeited						15.79	16.66
Options outstanding Ending Balance						$ 15.72	$ 15.07	$ 12.97
Intrinsic value of options exercised						$ 100,000	$ 0	$ 1,000,000
Number Outstanding as of December 31, 2016
Number Exercisable as of December 31, 2016						208,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term						4 years 4 months 10 days
Weighted Average Exercise Price (usd per share)						$ 14.83
Intrinsic value of stock options outstanding						$ 3,000,000
Intrinsic value of stock options exercisable						$ 1,000,000
Restricted Stock
Closing market price (in dollars per share)						$ 19.45
Weighted Average Grant Date Fair Value (per share)
Shares of restricted stock repurchased to satisfy tax withholding obligations						162,101	193,088	383,811
Aggregate intrinsic value of restricted shares						$ 19,100,000
Total unrecognized compensation cost related to non-vested restricted shares						8,100,000
Compensation expense related to restricted shares						6,400,000	$ 5,100,000	$ 4,900,000
Weighted Average Expected Option Phantom
Tax benefit attributable to all recorded stock-based compensation						$ 2,600,000	$ 2,400,000	$ 2,600,000
$12.97
Number Outstanding as of December 31, 2016
Number Outstanding as of December 31, 2016						810,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term						7 years 6 months 4 days
Weighed Average Exercise Price (usd per share)						$ 15.72
Stock Options And Employee Stock Purchase Plan
Weighted Average Grant Date Fair Value (per share)
Granted (usd per share)						$ 3.01	$ 3.13	$ 2.63
Fair value of equity instrument other than options						$ 163,000	$ 139,000	$ 102,000
Weighted Average Expected Option Phantom
Compensation expense related to options and ESPP rights						173,072	158,000	104,000
Cash received from exercise of options and ESPP						$ 900,000	$ 500,000	$ 900,000
Shares under the Amended and Restated 2009 Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock reserved for issuance					600,000
Shares available for future grants						294,165
Weighted Average Grant Date Fair Value (per share)
Employee Stock Purchase Plan (ESPP), Intrinsic Value of Purchased Shares						$ 121,000
Total unrecognized compensation cost, weighted-average recognition period						1 year
Percentage of compensation that participating employees can contribute to purchase common stock, minimum					1.00%
Percentage of compensation that participating employees can contribute to purchase common stock, maximum					15.00%
Common shares that participating employees can purchase in any plan year, shares					1,000
Percentage of discount from fair market value that eligible employees can purchase common stock					15.00%
Common shares that participating employees can purchase in any plan year, amount					$ 25,000
Shares issued under the ESPP	24,529	29,480	24,672	19,590		54,000	45,000
Shares issued under ESPP, weighted average price (usd per share)	$ 12.77	$ 12.61	$ 12.61	$ 9.36
Weighted Average Expected Option Phantom
Expected term						6 months	6 months	6 months
Risk-free rate, minimum						0.40%		0.05%
Risk-free rate, maximum						0.47%		0.06%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate							0.05%
Expected volatility, minimum						14.00%	17.40%	25.20%
Expected volatility, maximum						19.20%	23.80%	29.30%
Dividend Yield						0.00%	0.00%	0.00%
Intrinsic value of ESPP						$ 86,000
Unrecognized compensation cost related to non-vested stock options						$ 15,000
Stock Incentive Plan 1999
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock reserved for issuance					4,829,344
Shares under the 2009 Stock Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock reserved for issuance					1,000,000				2,700,000
Shares available for future grants						1,935,221
Shares under the 2009 Stock Incentive Plan | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options, terms					10 years
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share based compensation expense						$ 1,200,000	$ 500,000	$ 200,000
Weighted Average Expected Option Phantom
Expected term						6 years 3 months		3 years 9 months 1 day
Risk-free rate, minimum						1.54%	2.10%	1.40%
Risk-free rate, maximum						1.91%	2.30%	1.70%
Expected volatility, minimum						35.00%	38.30%	36.70%
Expected volatility, maximum						36.30%	47.30%	37.10%
Dividend Yield						0.00%	0.00%	0.00%
Stock options | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock awards, vesting period					4 years
Weighted Average Expected Option Phantom
Expected term							7 years
Stock options | Minimum
Weighted Average Expected Option Phantom
Expected term							6 years 3 months
Performance based restricted stock | Chief Executive Officer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share based compensation expense						$ 600,000	$ 400,000	$ 600,000
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized						$ 0
Restricted Stock
Granted (shares)						31,250
Unvested, Ending Balance (shares)						28,125
Weighted Average Grant Date Fair Value (per share)
Granted (usd per share)						$ 15.84
Restricted stock
Restricted Stock
Unvested, Beginning Balance (shares)						1,014,000	1,265,000
Granted (shares)						559,000	457,000
Vested (shares)						(429,000)	(470,000)
Forfeited (shares)						(163,000)	(238,000)
Unvested, Ending Balance (shares)						980,000	1,014,000	1,265,000
Weighted Average Grant Date Fair Value (per share)
Unvested, Beginning Balance (usd per share)						$ 13.11	$ 10.84
Granted (usd per share)						16.49	16.30	$ 11.73
Vested (usd per share)						12.76	11.15
Forfeited (usd per share)						14.06	11.07
Unvested, Ending Balance (usd per share)						$ 15.05	$ 13.11	$ 10.84
Fair value of equity instrument other than options						$ 5,500,000	$ 5,200,000	$ 9,000,000
Total unrecognized compensation cost, weighted-average recognition period						1 year 11 months 9 days
Restricted stock | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock awards, vesting period					4 years
Restricted stock | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock awards, vesting period					1 year